1. Field of the Invention
This invention relates to a ceiling fan.
2. Description of the Prior Art
A commonly seen ceiling fan generally includes a motor and a plurality of blades. The blades are firmly combined with the motor by means of fixing members provided on the outer casing of the motor.
As illustrated in FIGS. 1-2, a conventional ceiling fan, as disclosed in a U.S. Pat. No. 7,481,626, includes a motor 1 and a plurality of blades 2. The motor 1 has its outer circumferential side formed with a plurality of threaded cylinders 3, while each blade 2 has its inner side formed with plural protruding edges 4 respectively bored with plural insert holes 5 that correspond to the threaded cylinders 3, and the location and size of the insert holes 5 can be exactly combined and fixed with the threaded cylinders 3. Further, a plurality of locking fasteners 6 are provided to be respectively inserted through the insert holes 5 and threadably locked with the threaded cylinders 3 for securing the blades 2 on the motor 1.
However, after long-term use of the conventional ceiling fan and in the process of researching and developing ceiling fans, the inventor of this invention found that the blade assembly structure of the conventional ceiling fan can hardly lock and fix the blades 2 stably on the motor 1 and as a result, when the conventional ceiling fan is operated to rotate, the blades 2 are apt to sway, and the combination parts of the blades 2 and the motor 1 will produce vibration and give out abnormal sounds. Further, slight tolerance between the threaded cylinders 3 and the insert holes 5 makes it hard to have the insert holes 5 simultaneously aligned to the threaded cylinders 3 in a process of assembly of the ceiling fan, thus difficult in combining the blades 2 on the motor 1, taking a lot of work and time in assembly of the ceiling fan and hence lowering economic gains. Furthermore, the protruding threaded cylinders 3 at the outer circumferential side of the motor 1 must be made up by large-sized forming molds, rendering difficult in processing, high in manufacturing cost and thus unable to enhance market competitiveness.
In view of such drawbacks of the conventional ceiling fan, the inventor of this invention, who has been devoted to development and manufacturing of various types of ceiling fans and related components for many years and has much experience in marketing, constantly strives for perfection and thinks that the conventional ceiling fan has to be ameliorated and hence devises this invention.